Assessment of internal porosities for different placement techniques of bulk-fill resin-based composites: a micro-computed tomography study.

OBJECTIVES: The aim was to compare the porosity of different bulk-fill resin-based composites (RBCs) placement techniques to the conventional incremental technique using microcomputed tomography (µ-CT). MATERIAL AND METHODS: Occlusal cavities were prepared on extracted human molars, divided into five groups based on the placement technique (n = 10/group). Techniques examined were Monoblock-two-step (SureFil SDR flow + Ceram.X), Monoblock-two-step (Tetric EvoFlow Bulk-Fill + Tetric EvoCeram Bulk-Fill), Monoblock-one-step (Tetric EvoCeram Bulk-Fill), Monoblock with sonic activation (SonicFill2), and incremental technique (Filtek Z250). µ-CT scanning (SkyScan, Bruker, Belgium) assessed the number, volume of closed pores, and total porosity. Analysis of variance on ranks was used (Student-Newman-Keuls method and Mann-Whitney rank-sum test), to determine the significance of RBC viscosity and the sonication placement technique. The Spearman correlation method assessed the correlation between porosity characteristics (α = 0.05). RESULTS: The SonicFill2 presented a higher number of closed pores than the other groups (p < 0.05). The overall porosity within the restoration seemed greater in this order: Filtek Z250 > SonicFill2 > Tetric EvoFlow Bulk-Fill + Tetric EvoCeram Bulk-Fill > Tetric EvoCeram Bulk-Fill > SureFil SDR Flow + Ceram.X. Sonication was associated with increased number (p = 0.005) and volume (p = 0.036) of closed pores. A strong correlation was observed between the number and volume of closed pores (R2 = 0.549, p < 001). CONCLUSIONS: The monoblock technique with sonic activation showed significantly more internal porosity than the other placement techniques. Sonication during application contributed to the higher number and volume of closed pores than the passive bulk-fill application. CLINICAL RELEVANCE: Using bulk-fill materials enhances efficiency, yet void formation remains an issue, depending on viscosity and active/passive delivery of materials. Clinicians must familiarize themselves with effective placement techniques to reduce void formation and optimizing treatment outcomes.

The antiplaque/anticariogenic efficacy of Salvadora persica (Miswak) mouthrinse in comparison to that of chlorhexidine: a systematic review and meta-analysis.

BACKGROUND: The plant Salvadora persica (miswak) has a long history of use in oral hygiene. Associations between the use of Salvadora persica and decreased oral bacteria numbers and plaque scores have been reported. This systematic review and meta-analysis assessed the ability of Salvadora persica mouthrinses to reduce plaque/cariogenic bacteria, in comparison to that of chlorhexidine and/or placebo rinses. METHODS: A comprehensive literature search for clinical trials reporting the use of Salvadora persica rinses as an antibacterial and/or antiplaque agent in comparison with chlorhexidine and/or placebo rinses was conducted, with no restriction to language. MEDLINE-PubMed, Cochrane Central Register of Controlled Trials, Wiley Online Library, ScienceDirect, and Google Scholar databases were searched to include all articles published up to December 2018. Based on inclusion/exclusion criteria, data were extracted from the identified reports by two independent reviewers. The primary and secondary outcomes measured from the eligible studies were mean plaque scores and mean cariogenic bacterial counts, respectively. Risk of bias of these studies was assessed. A statistical test of homogeneity was used to determine if the results of the separate studies could be combined. Based on the chi-square test, an inconsistency coefficient was computed (I2 statistic). Sensitivity analyses using subgroups and homogeneity evaluation were conducted. RESULTS: A total of 1135 potentially eligible articles were identified, of which 19 were eventually included in the qualitative analysis whereas 18 were included in the quantitative meta-analysis. The meta-analysis showed that Salvadora persica rinses exhibited strong antiplaque effects (P < 0.00001, MD: 0.46, and 95% CI: 0.29 to 0.63). In addition, it had statistically significant anti-streptococcal (P < 0.0001, MD: -1.42, and 95% CI: -2.08 to - 0.76) and anti-lactobacilli effects (P < 0.00001, MD: -1.12, and 95% CI: -1.45 to - 0.79) when compared to placebo. However, its effects were inferior compared to those by chlorhexidine rinse (P = 0.04, MD: 0.19, and 95% CI: 0.01 to 0.37). Subgroup analyses yielded results similar to those prior to subgrouping. CONCLUSION: The use of Salvadora persica extract was associated with a significant reduction in the plaque score and cariogenic bacterial count. Although, this reduction was lower than that achieved with the gold standard chlorhexidine mouthwash, Salvadora persica-containing rinse could be considered as a suitable oral hygiene alternative for use in individuals of all ages, socioeconomic backgrounds, and health conditions especially as a long-term measure due to its efficacy, safety, availability, cost-effectiveness, and ease of use.

Effect of self-etch adhesives on the internal adaptation of composite restoration: a CP-OCT Study.

Despite improvements in dental adhesive materials, internal adaptation remains a challenge in bonded restorations. The aim of this study was to compare microgaps and internal floor adaptation between two different self-etch adhesives in class-V cavities using cross-polarization optical coherence tomography (CP-OCT). In this in vitro study, standardized round class-V cavities were prepared in 20 non-carious human upper central incisor teeth. They were randomly divided into two groups, TN and SE, with each group receiving a different dental adhesive. In TN group, the adhesive used was all-in-one Tetric N-Bond Self-Etch (TN; Ivoclar/Vivadent, Liechtenstein), while SE group was bonded with two-step self-etch Clearfil SE Bond 2 adhesive (SE; Kuraray Noritake Dental Inc, Japan). The prepared cavities were restored with flowable composite and then stored in distilled water for 24 h. Next, they were immersed in silver nitrate, followed by immersion in a photo-developing solution. Optical comparison was carried out by CP-OCT to assess microgaps and composite adaptation at the cavity floor. A Mann-Whitney test was applied to the data, which showed a statistically significant difference in composite adaptation among the two groups (p < 0.001) with the SE group showing superior adaptation. CP-OCT is a reliable tool for non-invasive imaging that gives an insight into composite performance. Better adaptation was found with the two-step self-adhesive for the composite used in this study.